1. Field of the Invention
This invention relates generally to sewing machines and more particularly to sewing machines provided with a threading hook which passes a thread through a needle eye.
2. Description of the Related Art
Conventional sewing machines comprise a threading apparatus including a threading hook coming close to and going away from a needle eye, a threading bar for supporting the hook, a threading lever joined with the threading bar, a holding member for holding a sewing thread at two locations, and a moving mechanism for moving the holding member near the needle eye. The threading apparatus is disposed above a movement range of the needle so as to be prevented from collision with the needle. In the foregoing threading apparatus, the threading lever is operated vertically so that the threading bar is moved downward together therewith. When the threading lever is moved downward to a lowermost position thereof, the threading hook is at the same level as the needle eye, so that the thread held by the holding member near the needle eye is passed through the needle eye.
Furthermore, conventional sewing machines comprise a swinging mechanism for swinging the sewing needle horizontally. The needle swung by the swinging mechanism forms a generally arcuate swinging locus. In such conventional sewing machines, the position of the needle eye differs depending upon a swinging location of the needle. In these conventional sewing machines, the threading bar and holding member are swung horizontally together with the needle bar for the purpose of reducing an adverse effect of the changes in the position of needle eye depending upon the swinging location of the needle. For example, JP-B-7-71596 discloses such a construction.
However, in the disclosed sewing machine, the threading lever is pressed down to a lowermost position and stopped once, and thereafter, the lever is released from the pressing operation before the threading operation is completed.
Therefore, an object of the present invention is to provide a sewing machine in which the thread can reliably be passed through the needle eye irrespective of the vertical position of the needle.
The present invention provides a sewing machine comprising a sewing needle moved up and down and having an eye, a threading hook passed through the eye of the needle, an urging member for urging the threading hook upward, an actuating member for moving the threading hook downward against an urging force of the urging member so that the threading hook is passed through the needle eye, a transmitting member moved between a transmission position where an operation of the actuating member is transmitted to the threading hook and a non-transmission position where an operation of the actuating member is not transmitted to the threading hook, a thread holding member for holding a thread, a moving mechanism for moving the thread holding member near to a position where the thread held by the thread holding member is located near the threading hook having been passed through the eye of the needle, and an abutting member abutting the transmitting member when the thread holding member has been moved to the position where the thread held by thread holding member is located near the threading hook having been passed through the eye of the needle, in order to move the transmitting member from the transmission position to the non-transmission position.
The operation of the actuating member is transmitted via the transmitting member to the threading hook upon operation of the actuating member. As a result, the threading hook is moved downward to be advanced through the eye of the needle. Continuously, when the thread holding member is moved by the moving mechanism to the near-by position, the abutting member abuts the transmitting member such that the transmitting member is moved to the non-transmission position. Accordingly, the operation of the actuating member cannot be transmitted to the threading hook. More specifically, the threading hook is returned to a former position after the thread held by the thread holding member has been moved near to the threading hook having been advanced through the eye of the needle. Consequently, the thread can reliably be passed through the eye of the needle.